"Misfueling"

[frank rabbets]

I've got a major problem with my VW golf and have been told I have used contaminated diesel or have misfueled it. I have talked to Shell Global Solutions laboratory and during the conversation they said that petrol separates out of the diesel in a few days. I then thought that someone could put a couple of gallons of petrol in their car and not think it would make a difference with a large dilution factor. Obviously if the petrol were to separate out this may cause a concentrated amount to get into the engine pump. I assume it separates to the top of the tank where it would be safer than the bottom? However if it were at the top you could have problems when running very low. That's two laboratories who have told me that now. Their first test is to put the fuel in a very thin tall glass tube to see any different layers which may appear.

Frank

 

[yogi]

Surely Frank you would know if you had mis fuelled it?

I would have thought that would have become obvious at the time?

Inadvertantly buying laundered diesel seems a bit ,more likely to me?

The fractions will separate out in a tall thin tube, but I find it unlikely to happen in the tank due to motion and its shape.

 

[yogi]

Just out of curiosity do you always buy your diesel in the one spot, or are you a fill it when its empty where you are kind of guy?

The chemicals used to wash diesel are particularly harmful to the more sophisticated modern common (blah blah) direct whatever type diesels like your golf. They are relatively harmless in a big old lump like in your 80 series.

Here in Ireland laundered diesel is frighteningly common, and there have been lots of wrecked engines.

 

[Shayne]

Whether it separates or not surely the only way forward is to drain the tank and change the filters .

 

[wobbly]

Was this the starting problem you had last week?

Problem will be if its been run for a protracted period on diesel/petrol mix, there are two side effects - the combustion will be hotter than diesel alone, but also there will be a 'double combustion' - the diesel ignites when compressed, and that ignition then ignites the petrol.

Putting in a tiny amount of petrol was a way of improving diesel power, but that was prior to common-rail / direct injection engines.

Do you keep your fuel receipts, if so id have a look through them.....

Pete

 

[frank rabbets]

Yes this was the starting problem thread. The garage have followed the correct procedure and replaced some bits but again it would not start for them after a few drive arounds. They ran out of options and checked the fuel filter bowl and this has fine metallic particles floating about in the fuel. Now their protocol says they have to change the entire fuel system but they cannot be 100% sure that this will cure the poor starting. They say contaminated fuel might have been used which lead me to see about a fuel test. They have not charged me for the work done.

I do not use the same garage or keep my receipts. I think you would have a job proving that a certain garage served you contaminated fuel unless you kept a sample each time. The dealer would say it was the fuel and the station would say it was a poor pump. Instant blown up engine on the forecourt and poor fuel in the tank would be OK.

Assuming I have contaminated fuel damage the contamination could have occurred a long time ago. The fuel pressure is normal and the engine has been run on the VAG computer and everything is normal so nobody can understand this poor starting issue. We are now running the car normally as the swarf is not getting past the filter so no further damage should be happening.

Yogi I agree the 80 would not suffer as easily and yes the motion of the car could keep the 2 fuels mixed up.

Frank

 

[yogi]

"I do not use the same garage or keep my receipts. I think you would have a job proving that a certain garage served you contaminated fuel unless you kept a sample each time. The dealer would say it was the fuel and the station would say it was a poor pump. Instant blown up engine on the forecourt and poor fuel in the tank would be OK."

Fully agree that it would be very hard to prove anything Frank. Its just that shopping around increases your chances of buying washed diesel, that was more the point I was trying to make for everyones benefit. Saving that 0.5p a litre at the pump can be very expensive in the long run. You wouldn't put oil in your engine that came out of a 50 gallon drum without a label on it so I can't really figure why people don't treat fuel/diesel the same way!

Liam

 

[wobbly]

I only use one petrol station, and as it all goes through the business, keep all receipts.

The metallic particles are odd, there must be something wearing downstream of the filter.

As the engine needs a high quality fuel, I'd've thought the contamination would be more recent.

After driving the car, draw off some fuel and put it in a clear plastic bottle. It will settle very quickly. Different layers will point to contamination.

Pete

 

[Gary820]

Are they magnetic particles or non magnetic?
Get it in Beemers and if it's magnetic there's an issue usually with the pump. Non magnetic no issue. Thats the official guides we have to determine damage if diesels have been misfuelled.

 

[frank rabbets]

I'm taking the top off the fuel filter body after Boxing day. The pump runs at full pressure. The particles looked like aluminium and the magnet tip is a good idea. If it is pump damage I wonder if the damage may be over with and the pump will have a long life?

Frank